| 摘要 |
<p>The pilot-valve-controlled safety valve is for use with pipes and vessels under high pressure. A valve operating in two stages, through which the medium normally does not flow, controls one of considerably greater capacity. Flow-regulation members perform the positive valve function and work with the first stage, and the main valve is pref. mounted directly on the vessel to be protected. A flow adaptor (100) with a self-cleaning opening is mounted between the main chamber (68) of the main valve and ports leading to the pilot valve. A ball (16) is mounted in a selector (24,15) to allow testing of either the pilot valve the complete valve. The pilot valve acts on the main one in proportion to the amount of excess pressure. A partially pressure-balanced valve unit of large dia. and joints of smaller dia. increases sensitivity to excess pressure. A ball-valVe forms a stopcock for testing gas.</p> |
